1. Technical Field
The present invention relates to the production of a low carbohydrate sheetable dough that can be made into a shelf stable snack food with minimal reduction of organoleptical properties.
2. Description of Related Art
Shelf stable snack food products such as tortilla chips are popular consumer items for which there exists a great demand. Tortilla chips are typically made from corn. The corn from corn tortilla chips such as those in the snack food industry is sometimes cooked and soaked prior to being made into a flour, dough, or masa. One example of this process is the treatment of corn in nixtamalization process—the traditional method for processing fresh corn to form masa dough. This process dates back to the pre-Columbian era of the Aztec and Maya people in Mesoamerica. In the traditional nixtamalization process, fresh whole-kernel corn is first soaked in absolution of water and lime (calcium hydroxide) and then partially cooked at or near the boiling point for a short time depending on the hardness of the corn. The corn is then steeped in the limewater solution and is allowed to cool for about 8-18 hours in order to loosen and degrade the pericarp (or bran), which is the outer, fibrous layer of a corn kernel. Cooking and steeping in alkaline solution causes partial dissolution of the cuticle and other pericarp layers as well as swelling and weakening of cell walls and fiber components. The corn kernels are then drained of the cooking liquor (called “nejayote”), which contains loosened pericarp and other dissolved or suspended particles, and the corn kernels are washed to remove excess lime and loose particles. Typically, up to 15% by weight of the total corn fraction is lost during the cooking and washing steps. The corn kernels are then ground to disrupt the starch-containing cell structures and cause the mixture to gelatinize. The ground, wet mixture can be mixed with water to form fresh masa dough, or it can be dehydrated to form dry masa flour. Dry masa flour can be rehydrated at a later time to form masa dough. Unfortunately, corn is a high carbohydrate food. The carbohydrate calories present in a traditional tortilla chip are derived primarily form the corn content.
Recently, consumer demand for products low in carbohydrates has dramatically increased, as the popularity of low carbohydrate diets has increased. According to one recent newspaper account, 40% of consumers say they are watching their carbohydrate intake. There are currently numerous low carbohydrate diets being marketed to consumers. Such an example is exemplified by U.S. Pat. No. 5,855,949, which discloses a dietary system for the treatment of obesity that prescribes foods that are low in fats and carbohydrates, and which have moderate amounts of proteins. Unfortunately, the '949 patent fails to disclose a means for reducing carbohydrate intake from snack foods. U.S. Patent Application 2003/0108654 A1 discloses a dry mix and process for using said mix to make a low carbohydrate potato product. Dry mixes are not usually considered “ready to eat” foods, as water must first be added and the resulting dough composition mixed and cooked prior to consumption. In addition, the application indicates that the product made from the dry mix are not shelf stable unless dried. If the products are dried, though, they may not be ready to eat. Thus, the invention disclosed in the '654 application fails to provide a convenient, ready to eat, shelf-stable, and low carbohydrate snack food. Hence, there is a need for a convenient low carbohydrate shelf-stable, ready to eat snack food.
Many convenient, shelf-stable, ready to eat snack foods are high in carbohydrates. This reality makes it difficult for consumers to maintain a low carbohydrate diet. In addition, many consumers have become accustomed to supplementing their meals with convenient snack foods, adding more difficulty to maintaining a low carbohydrate diet.
One solution for a low carbohydrate snack food is illustrated in U.S. Patent Application No. 2003/0064145 A1, entitled “Puffed Protein Based Snack Food.” The '145 patent application discloses a low-density snack food comprising a solids matrix of protein, an optional carbohydrate filler in a fat content not to exceed 30%. The taste and texture characteristics of this product, however, fail to mimic the taste and texture characteristics of a conventionally produced puffed snack product. For example, there is no discussion in the disclosure how the off flavors known to inherently develop in extruded high protein compounds, were avoided. This disclosure however, is directed towards direct expanded food products rather than tortilla-like snack products.
Another attempt to solve this problem is disclosed in U.S. Pat. Nos. 6,291,009 and 6,479,089, which disclose a soy based dough and products made from the dough. These patents, however, use either derivatives of roasted or toasted soybeans such as full fat soy flour or other soy flour, or soy protein concentrates or isolates. Further, soy protein concentrate and soy protein isolates do not break down during mastication forcing the consumer to continue to feel the need to chew for a longer period of time. Thus, it is desirable to minimize use of soy protein isolates and soy protein concentrates as ingredients, however, because of poor mouth feel and texture attributes. Further, soy protein concentrates and soy protein are relatively expensive compared to unprocessed raw ingredients. For example, soy protein isolates and soy protein concentrates can cost ten times or more the cost of raw soybeans. Moreover, full fat soy flour and other soy flours are typically produced from whole soybeans that have been heat treated (e.g. toasted and roasted) to deactivate enzymes and trypsin inhibitors, and then milled. As a result, full fat soy flour and other soy flours usage at high levels similarly produce products with poor mouth feel, texture and flavor attributes.
Consequently, there is a need in the art for a process for manufacturing reduced carbohydrate snack product with taste and texture characteristics similar to conventionally produced snack products. Further, there is a need in the art for a process for manufacturing reduced carbohydrate tortilla-like snack product with taste and texture characteristics similar to conventionally produced corn tortilla snack products. The low carbohydrate snack food should emulate the organoleptical properties, including taste and texture, of a conventionally produced corn tortilla snack product. The snack food should be shelf stable and ready to eat.